转码刷题每日打卡贴

每日刷题打卡+udacity刷项目，新的一年加油加油！！

2021-01-13:
Merge K Sorted Arrays - heap/merge sort
Anagrams - hashmap
Longest Consecutive Sequence = hashmap
Copy List with Random Pointer - hashmap
Insert Delete GetRandom O(1) - Duplicates allowed - hashmap + set + array

2021-01-05:
LRU Cache - 手动实现
Ugly Number II - heap
K Closest Points - max heap nlogk
Top k Largest Numbers II - heap
Subarray Sum - prefix sum
Top k Largest Numbers - heap/quickselect+quicksort

2022-01-03：
Heapify
heap sort
First Unique Number in Data Stream
First Unique Number in Data Stream II - hashmap + linkedlist
Insert Delete GetRandom O(1) - hashmap + list

2022-01-02：
Hash function
Rehashing
What is a heap, insert - O(logN), pop - O(logN), remove - O(logN) need a hashmap to find the element quickly, sift up/down

2022-01-04：
LRU - hashmap + linkedlist (single/double)
OrderedDict

2022-01-06

感冒。。。

2021-01-09
Trie
Implement Trie (Prefix Tree)
Add and Search Word - Data structure design

2021-01-10：
word search
word search II 用trie 和不用trie

2021-01-12:
word search III - word searchII 基础上，只能同时，不能公用单词，求最多单词的个数
Maximum XOR of Two Numbers in an Array - Trie 或者 贪心+two sum hash